ELECTROENCEPHALOGRAPHIC CORRELATES OF MARIJUANA-INDUCED EUPHORIA

The present study was conducted to determine if there is a neurophysio logical correlate of marihuana-induced good effects or euphoria. Three groups of 6 male occasional marihuana smokers were prepared for elect roencephalographic (EEG) recording and smoked either placebo or marihu ana cigarettes containing 1.26% or 2.53% Delta(9)-tetrahydrocannabinol (Delta(9)-THC) in a controlled laboratory setting. Using a continuous ly available non-verbal joystick device and a questionnaire, subjects reported changes in their subjective mood state while EEG activity was continuously recorded. Subjects reported multiple episodes of intense good effects or euphoria during the first 15 min after marihuana. The se episodes of euphoria occurred while plasma Delta(9)-THC levels were rapidly rising. EEG alpha power during these discrete episodes of eup horia was significantly higher suggesting that these transient EEG cha nges may reflect a neurophysiological correlate of the reinforcing eff ects of marihuana.